This invention pertains to cargo transportation, and more particularly to an apparatus that facilitates loading and unloading of cargo from a vehicle. It is well known in the art to install retractable platforms on the beds of trucks to support and move the truck cargo. However, the prior art devices are unnecessarily complex, and therefore are not practical for varying applications.
U.S. Pat. No. 5,052,878 and 4,950,123, both issued to Brockhaus, describe retractable truck beds involving telescoping cargo supports that are unnecessarily complicated. Other examples of such structures may be seen in U.S. Pat. Nos. 4,305,695, 4,303,367 and 4,268,213.
A primary difficulty in designing and constructing such platforms is obtaining sufficient cargo carrying capacity and travel from light weight materials while maintaining design simplicity. Platform designs should incorporate greater structural strength and rigidity such that platforms are self supporting. This design criteria eliminates the need for vertical support when the platform is extended and allows that platforms of varying sizes for different applications can be manufactured at a relatively inexpensive cost.
It is important that the platform is light weight, so that a single user can install and remove the platform without the need of assistance. Furthermore, improved means for locking the platform frame in place on the vehicle is also desirable. Thus, a need exists for improvements in retractable truck beds.